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Hello everyone, this is Kori and today we are going to continue talking about heat and light.

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First we will discuss heat and matter. Heat is a form of energy that passes from a hotter object

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to a colder one and matter is something that takes up space and has mass. Things like air,

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Air, water, rocks, and people are all examples of matter.

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If matter absorbs heat, its temperature increases.

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It gets warmer.

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So when you cook food, your food absorbs heat.

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It takes in heat.

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The temperature of your food increases

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and the food gets warmer.

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If matter emits heat,

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temperature decreases, it cools down. So when an animal gives off or emits heat

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its temperature decreases. The temperature goes down which means it's

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cooling down and the animal is getting colder as it emits heat. If two objects

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with different temperatures come into contact, heat transfers from the

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hotter object to the colder one and they are the same temperature. So we are going

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to see this in these pictures here. First let's look at the one on the left. In

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In this picture, you can see that a glass of hot water is put into a pan of colder water.

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The thermometer tells us that the temperature of the glass of water is 90 degrees Celsius.

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The temperature of the water in the pan is 40 degrees Celsius.

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obvious. These objects have different temperatures. Can you guess which way the heat will transfer?

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Remember, when objects are in direct contact, meaning they are right next to each other,

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heat moves from the hotter one to the colder one. In this example, heat would be transferred

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from the 90 degree cup of water to the 40 degree pan of water.

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Eventually the water in the cup and the water in the pan will be the same temperature.

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We can see this in the second picture.

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The thermometer tells us that the temperature of the water in the cup is 60 degrees Celsius.

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and the water in the pan is also 60 degrees celsius. They are now the same temperature.

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If matter gets hot, it usually gets bigger. It expands. We see this when we're baking

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muffins or cakes or bread. A cake will get bigger when it's cooked. It expands as it gets warmer.

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If matter cools down, it usually gets smaller. It contracts. So here's a tip to help you remember

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this. When you are cold, you typically bring your arms in close to your body and you make yourself

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smaller. As matter gets colder, it contracts and gets smaller, just like how you make yourself

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smaller when you're feeling cold. Water, however, is a special case. Water does the opposite.

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Water increases in size when it freezes. So water gets bigger when it freezes. This is different

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than other types of matter. Other types of matter typically get smaller when

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they get colder. Conducting materials let heat pass through them. Conducting

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materials are called conductors. Many types of metals are good conductors. This

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is why we cook with metal pans. Non-conducting materials do not let heat pass through them.

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Non-conducting materials are called insulators. The tires or wheels on cars are made of rubber,

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which is an insulator. Plastic and wood are also insulators. When you cook, you probably stir your

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food with a spoon or spatula made of an insulator. This keeps your hands from getting too hot.

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If you tried to cook with a conducting material to stir your food, the spoon would get really hot.

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The heat would transfer from your stove, to the pot, to the spoon,

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and then to your hand, and your hand would get burned. Ouch. So if you use an

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insulator to stir your food when you're cooking, the insulator will protect you

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from getting burned because heat cannot pass through an insulator. Now we are

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going to talk about the three states of matter. Solid, liquid, and gas. Solid

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matter is rigid. It is not flexible and it does not move around. Solid matter has

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a fixed shape and a fixed volume. It stays as it is.

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Solids cannot be squashed. You probably see lots of examples of solids around

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you now. Solids are things like a chair, a rock, a table, or a car. Liquid matter is

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not rigid. It has no fixed shape. Liquids take on the shape of the container they

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in. Liquids have a fixed volume. This means that they always take up the same

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amount of space. Liquids cannot be squashed. Liquids include things like

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water, juice, or coffee. Gas is not rigid. It does not have a fixed shape and gas

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does not have a fixed volume. Gas can be squashed. Gases move around freely. You

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can put your hand through a gas and not feel anything. There are gases in the air

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that we breathe and in the steam coming off of soup or tea. Matter can change

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state. When a solid changes into a liquid, we call that melting. When a liquid

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changes into a gas, we call that evaporation. When a solid changes into a

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gas, we call that sublimation. Here we have a diagram showing you how matter

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can change state. When the arrows are moving to the right from solid, liquid, to

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gas, the matter is getting warmer. When the arrows are moving to the left from

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gas, liquid, to solid, the matter is getting colder. Solid to gas, sublimation.

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solid to liquid melting liquid to gas boiling gas to solid deposition gas to

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liquid condensation and liquid to solid freezing alright I hope you found this

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helpful have a great rest of your day and goodbye for now